Heat Pipe and Method for Manufacturing Same

Abstract

A small and thin heat pipe with enhanced heat conductivity. Between an upper member having a grid-like upper concave portion on an inside lower surface and a lower member having a grid-like lower concave portion on an inside upper surface are provided intermediate plate members. The members are each formed with multiple vapor diffusion flow paths extending in a planar direction, communicating with the concave portions of the members, respectively. Thus, a sealed space is defined therebetween so that a refrigerant is enclosed therein. Capillary flow paths are formed through a portion of the members except where the vapor diffusion flow paths are formed such that the capillary flow paths extend vertically or both vertically and horizontally, communicating with the concave portions of the members.

1 : A heat pipe comprising:
 an upper member, said upper member being tabular, having a concave portion on a lower surface;   a lower member, said lower member also being tabular, having a concave portion on an upper surface;   one or more intermediate plate members, said one or more intermediate plate members being tabular, provided between said upper member and said lower member, each intermediate plate member including a plurality of vapor diffusion flow paths extending in a planar direction, communicating with the concave portions of said upper and lower members to form a sealed space defined by said upper and lower members with said vapor diffusion flow paths and said concave portions being included therein;   a refrigerant enclosed in said sealed space; and   capillary flow paths formed through a portion of said one or more intermediate plate members except where said vapor diffusion flow paths are formed, said capillary flow paths extending vertically or both vertically and horizontally, communicating with the concave portions of said upper and lower members,   wherein said intermediate plate members are more than one, each intermediate plate member having a through-hole formed therethrough, such that the through-holes of said intermediate plate members are overlapped only partially by stacking said intermediate plate members to define said capillary flow path having a planar cross-sectional area narrower than that of said through-hole.   
   
   
       2 . (canceled) 
   
   
       3 . (canceled) 
   
   
       4 : The heat pipe according to  claim 1 , further comprising a plurality of projections integrally formed on an outer surface of at least one of said upper and lower members so that a device to be cooled may be mounted thereon. 
   
   
       5 : A heat pipe comprising:
 an upper member, said upper member being tabular, having a concave portion on a lower surface;   a lower member, said lower member also being tabular, having a concave portion on an upper surface;   one or more intermediate plate members, said one or more intermediate plate members being tabular, provided between said upper member and said lower member, each intermediate plate member including a plurality of vapor diffusion flow paths extending in a planar direction, communicating with the concave portions of said upper and lower members to form a sealed space defined by said upper and lower members with said vapor diffusion flow paths and said concave portions being included therein;   a refrigerant enclosed in said sealed space; and   capillary flow paths formed through a portion of said one or more intermediate plate members except where said vapor diffusion flow paths are formed, said capillary flow paths extending vertically or both vertically and horizontally, communicating with the concave portions of said upper and lower members,   wherein said upper and lower members have a rectangular planar shape, respectively, while a device mounting section for mounting a device to be cooled thereon is arranged in the center of said heat pipe, with each of said vapor diffusion flow paths extending in an oblique direction relative to sides of said heat pipe.   
   
   
       6 : The heat pipe according to  claim 1 , wherein said upper and lower members have a rectangular planar shape, respectively, while a device mounting section for mounting a device to be cooled thereon is arranged in the center of said heat pipe, with each of said vapor diffusion flow paths extending in a radial direction from said device mounting section. 
   
   
       7 . (canceled) 
   
   
       8 : The heat pipe according to  claim 1 , wherein joining projections are formed in a peripheral portion of each of said upper member, one or more intermediate plate members and lower member as well as from a peripheral portion of said device mounting section to a neighborhood thereof, so that said upper member, one or more intermediate plate members and lower member are joined directly to each other by hot pressing to said joining projections. 
   
   
       9 . (canceled) 
   
   
       10 : A method for manufacturing a heat pipe, comprising the steps of:
 preparing a lower member of a tabular shape, having a concave portion on an upper surface thereof; an upper member of a tabular shape, having a concave portion on a lower surface thereof; and two or more intermediate plate members provided between said upper member and said lower member, each intermediate plate member being of a tabular shape, including a plurality of vapor diffusion flow paths extending in a planar direction, communicating with the concave portions of said upper and lower members;   superimposing said members with one upon top of another;   forming a capillary flow path having a planar cross-sectional area narrower than a through-hole formed through each of said intermediate plate members due to said through-holes of said intermediate plate members being partially overlapped by stacking said intermediate plate members;   applying hot pressing to joining projections, said joining projections being formed from peripheral portions of said lower, upper and two or more intermediate plate members where said members are to be joined directly to each other to a neighborhood thereof; and   joining said upper, lower and two or more intermediate plate members together directly relative to each other in positions where said joining projections are formed.   
   
   
       11 : The heat pipe according to  claim 1 , further comprising:
 one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;   a refrigerant enclosed in said sealed space; and   a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal.   
   
   
       12 : A heat pipe comprising:
 an upper member, said upper member being tabular, having a concave portion on a lower surface;   a lower member, said lower member being tabular, having a concave portion on an upper surface;   one or more intermediate plate members, said one or more intermediate plate members being tabular, provided between said upper member and said lower member, each intermediate plate member including a plurality of vapor diffusion paths, communicating with the concave portions of said upper and lower members, said respective members being superimposed with one upon top of another to form a sealed space defined by said upper and lower members with said vapor diffusion flow paths and said concave portions being included therein;   one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;   a refrigerant enclosed in said sealed space;   a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal; and   one or more degassing grooves formed on a peripheral inner surface of each of said refrigerant charging openings, wherein said degassing groove keeps an interior space communicated with an exterior space until each refrigerant charging opening is sealed fully by said sealing plug, while said degassing groove is sealed by said sealing plug when each refrigerant charging opening is sealed fully by said sealing plug.   
   
   
       13 . (canceled) 
   
   
       14 : The heat pipe according to  claim 12 , wherein each refrigerant charging opening has a larger diameter in an upper portion thereof than in a lower portion thereof, while a surface of said sealing plug for sealing each refrigerant charging opening is not protruded from an outer surface of the member formed with said refrigerant charging opening. 
   
   
       15 : The heat pipe according to  claim 1 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       16 : The method for manufacturing a heat pipe, according to  claim 10 , wherein after said joining step the method further comprises the steps of:
 supplying a refrigerant into a sealed space defined by said upper and lower members through one or more refrigerant charging openings formed through at least one of said upper and lower members, under reduced pressure; and   placing a ductile metallic body serving as a sealing plug in each refrigerant charging opening, and then applying pressure to said ductile metallic body to thereby provide said sealing plug for sealing each refrigerant charging opening.   
   
   
       17 : The heat pipe according to  claim 11 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       18 : The heat pipe according to  claim 4 , wherein joining projections are formed in a peripheral portion of each of said upper member, one or more intermediate plate members and lower member as well as from a peripheral portion of said device mounting section to a neighborhood thereof, so that said upper member, one or more intermediate plate members and lower member are joined directly to each other by hot pressing to said joining projections. 
   
   
       19 : The heat pipe according to  claim 11 , wherein each refrigerant charging opening has a larger diameter in an upper portion thereof than in a lower portion thereof, while a surface of said sealing plug for sealing each refrigerant charging opening is not protruded from an outer surface of the member formed with said refrigerant charging opening. 
   
   
       20 : The heat pipe according to  claim 4 , wherein said upper and lower members have a rectangular planar shape, respectively, while a device mounting section for mounting a device to be cooled thereon is arranged in the center of said heat pipe, with each of said vapor diffusion flow paths extending in a radial direction from said device mounting section. 
   
   
       21 : The heat pipe according to  claim 5 , wherein joining projections are formed in a peripheral portion of each of said upper member, one or more intermediate plate members and lower member as well as from a peripheral portion of said device mounting section to a neighborhood thereof, so that said upper member, one or more intermediate plate members and lower member are joined directly to each other by hot pressing to said joining projections. 
   
   
       22 : The heat pipe according to  claim 6 , wherein joining projections are formed in a peripheral portion of each of said upper member, one or more intermediate plate members and lower member as well as from a peripheral portion of said device mounting section to a neighborhood thereof, so that said upper member, one or more intermediate plate members and lower member are joined directly to each other by hot pressing to said joining projections. 
   
   
       23 : The heat pipe according to  claim 4 , further comprising: one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;
 a refrigerant enclosed in said sealed space; and   a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal.   
   
   
       24 : The heat pipe according to  claim 5 , further comprising: one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;
 a refrigerant enclosed in said sealed space; and
 a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal. 
   
   
   
       25 : The heat pipe according to  claim 6 , further comprising: one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;
 a refrigerant enclosed in said sealed space; and
 a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal. 
   
   
   
       26 : The heat pipe according to  claim 8 , further comprising: one or more refrigerant charging openings formed through one of said upper and lower members, said charging openings allowing said sealed space to communicate with an exterior space;
 a refrigerant enclosed in said sealed space; and
 a sealing plug for sealing each of said refrigerant charging openings, said sealing plug being made from ductile metal. 
   
   
   
       27 : The heat pipe according to  claim 4 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       28 : The heat pipe according to  claim 5 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       29 : The heat pipe according to  claim 6 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       30 : The heat pipe according to  claim 8 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       31 : The heat pipe according to  claim 12 , wherein an interior of said sealed space is under reduced pressure. 
   
   
       32 : The heat pipe according to  claim 14 , wherein an interior of said sealed space is under reduced pressure.